Related Applications
There are no applications related hereto heretofore filed in this or any foreign country.
Field of Invention
My invention relates generally to measuring and testing instruments and more particularly to an air flow meter for use in speech therapy to measure air flow from nasal or oral cavities during speech.
Description of Prior Art
The production of speech is a complex interreaction of physical, physiological and psychological phenomena wherein a speaker's respiration moves a stream of air through the larynx, which impresses it with acoustic energy by a process known as phonation, and subsequently through the oral and nasal cavities where it is resonated and restructured by a process known as articulation to produce an aurally perceivable, comprehensible, energy that we call speech. The process is sufficiently complex that until the recent past, at least, it has been dealt with, understood and analyzed largely subjectively by its audio results rather than by means of any objective scientific measuration. The instant invention seeks to provide an instrument that objectively measures some forms of speech quality and particularly one which measures, either absolutely or comparatively, the flow of air from either nasal or oral passages for use principally in speech therapy, either as a diagnostic or remedial tool.
Most normal speech articulation is carried on in the oral cavities. Undoubtedly because of this, most attention in speech therapy has been directed toward various aberrations of these activities in the oral cavities rather than aberrations that may occur in the nasal cavities. Resonance in the nasal cavities, however, is a necessary part of certain elements in speech, particularly as in the case of the three semi-vowels of English /m/ as in 'mummy', /n/ as in 'nancy' and /n/ as in 'singer', all of which are produced with a complete occlusion of the oral cavity. Various similar aberrations of resonance and air passage in the nasal cavity, as in hypernasality, denasality, assimilated hypernasality and nasal air emission, must oftentimes be diagnosed and dealt with remedially in speech therapy. The problems associated with nasal resonance and air passage have probably been the most neglected areas of speech and language therapy and have generally presented a confusing area of semi-knowledge, as evidenced by the literature, brought about principally by subjective measurements and a lack of tools for objective measurement.
By far the bulk of nasal air flow and resonance problems have heretofore been analyzed and treated on the basis of subjective audio analysis of a speech and language by a therapist. This procedure, with its lack of objective standards in the measuration and testing, has produced a bewildering array of information which is about as varied as the subjective standards of the therapists involved. In the recent past some objective standards of measuration have been applied to nasal air emissions in therapy, centered principally about two measuration principles; the first, a liquid filled manometer, and the second, a mechanical pressure gauge. Neither of these methods of measurement have proven completely successful because each in essence measures a static pressure at a particular instant of time rather than a dynamic rate of air flow from the nasal cavity over an elapsed period and generally by reason of the manner in which the measurement is made, normal air flow from the nasal cavity must be stopped or at least substantially modified during the measuration per se and ordinarily for a period of time both before and after, all of which tends to effect resonance in the nasal cavity and thusly the articulation that is sought to be measured in the first instance. These known methods of measuration of nasal air pressure thusly have not proven too effective as they do not directly measure the condition sought to be determined, and change that condition by reason of the measurement.
Cineflurography and spectrographic analysis of voice samples have also been used somewhat in the recent past in analyzing and dealing with problems of nasal articulation. Both processes, however, are complex, relatively difficult and expensive and often not readily available to many speech therapists. Each process, again, is only indirectly related to problems of nasal resonance or air flow as each measures secondary characteristics of the acoustics or physiology related thereto. Neither process has proven satisfactory or been accepted in analyzing and treating problems of nasal articulation in speech therapy.
The instant invention seeks to provide a new clinical tool to continuously measure and indicate the existence, quality and quantity of air flow from the nasal cavities during normal speech activities without affecting those cavities during the process, to serve as both a diagnostic and remedial tool for a therapist. The instant invention is readily distinguishable from the pressure gauge type devices hereinbefore described in that it measures the existence, quality and quantity of the air flow from the nasal cavities rather than the pressure of that air within those cavities at a particular time. In so doing my device does not substantially affect the air flow from the nasal cavities and therefore does not affect the articulation processes therein as do the manometric type measuring devices. My invention is distinguished from the cineflurographic type devices in that the two devices measure different things, my device measuring air flow while the cineflurographic device measures anatomical position of various of the peripheral elements defining the nasal cavity. Similarly my device is distinguished from the voice spectrograpic analyzers in that they measure the acoustical quality and quantity of sounds produced from the whole vocal channel, including the articulation processes of both the oral and nasal cavities, which make it difficult, if even possible, to separately analyze the nature and quality of nasal articulation.
Secondarily my invention with an appropriate interchangeable oral receptor may also measure quantity and quality of air flow from the oral cavity, especially outwardly of the teeth and between the lips. The oral receptor is small enough to distinguish the lateral position of an emission from the oral cavity. It is therefore especially useful with lateral sibilant, fricative and affricative sound productions, aberrations and modifications.
My invention also provides a measuration tool that is portable, of relatively small size and of economic manufacture so that it may be readily available to therapists and others concerned with speech problems for general use in nonclinical surroundings, whereas this is not the case with the more sophisticated and costly devices of the prior art.
My invention thusly differs in both structure and function from known devices providing measurements relating to oral or nasal articulation either individually or collectively in that the known devices do not measure air flow and may change conditions of speech processes during measuration.